Uniform Determination of Death Act (UDDA):
Uniform Determination of Death Act (UDDA):
Uniform Determination of Death Act (UDDA):
Neurologic criteria for death were recognized in roughly half of the United States by the end of the 1970s, creating a confusing legal landscape. The President’s Commission for the Study of Ethical Problems in Medicine and Biomedical and Behavior Research recommended that state legislators adopt the Uniform Determination of Death Act (UDDA)1 to achieve uniformity across state lines and alignment of the law with medical practice.
A person who has died has either sustained irreversible cessation of circulatory and respiratory functions or sustained irreversible cessation of all functions of the entire brain, including the brainstem. Death must be determined in accordance with accepted medical standards.
Despite serving as a model statute for 40 years and being adopted in whole or in part throughout the United States2, there is growing recognition that the UDDA needs to be updated.
3,-,5 The Uniform Law Commission recently approved the recommendation of a Study Committee to form a Drafting Committee, which will submit proposed UDDA revisions by July 2023. Meanwhile, Nevada, Oklahoma, and Texas have already taken steps to amend their respective UDDA statutes (NV. A.B. 424 , Okla. H.B. 1896 , Tex. H.B. 4,329 ). The interpretation of the phrases “all functions of the entire brain” (vs some specific set of functions) and “accepted medical standards” (should they be specifically named?) and whether accommodations are required to address religious or principled objections to determining death by neurologic criteria are contentious aspects of the UDDA (DNC). 6,-,9 We propose a solution to the alleged inconsistency between the meaning of “all functions of the entire brain” and “accepted medical standards” by shifting from an anatomical to a functional approach to DNC, similar to the approach to death by circulatory criteria. This change will bring the law in line with medical practice, increase examiner confidence in the reliability of currently accepted medical standards, and clearly communicate to the public what the standards are expected to assess.
DNC medical standards that are currently accepted (published by the American Academy of Neurology in 2010 and the Society of Critical Care Medicine, American Academy of Pediatrics, and Child Neurology Society in 2011)
Documentation of an injury that explains the loss of brain function, the exclusion of confounding conditions, and a clinical examination that demonstrates unarousable unresponsiveness, brainstem areflexia, and apnea are all required in cases 10,-,12. Some argue that the absence of diabetes insipidus in many people who meet these criteria indicates that some brain functions, specifically those in the neurosecretory hypothalamus that regulate salt and water balance, continue after death. 13,14 With this in mind, a Nature editorial argued, “The time has come for a serious discussion on redrafting laws that force doctors into deception.” 15(p570) To bring the law into line with practice, either the “accepted medical standards” must include a more stringent set of tests that exclude neurosecretory functioning, or the text requiring the cessation of “all functions of the entire brain” must be revised. 16,17
The criteria used to determine death must, at some level, be a matter of convention and consensus.
18,19 The pertinent question is not whether any brain functions remain, but whether those functions contradict a death determination. Unlike consciousness, responsiveness, or spontaneous respiratory effort, the presence of neurosecretory functioning is not recognized as a contradiction to the determination of death outside of a discussion about the phrase “all functions of the entire brain.” 20,-,25 While we welcome further discussion on its significance, we see no reason to reject the recommendations of consensus statements such as the World Brain Death Project26 that neurosecretory function persistence is consistent with DNC.
As a result, we support revision of the UDDA to more precisely specify legal criteria that align with medical standards: brain injury resulting in permanent loss of (a) consciousness, (b) spontaneous breathing, and (c) brainstem reflexes.
3,4 These new criteria are known as “neurorespiratory criteria.” We recognize that there may be different and competing reasons why neurorespiratory criteria are appropriate, and we even disagree on this, but we all agree that the law would be more clearly aligned with practice if the phrase “all functions of the entire brain” was replaced with language clearly specifying neurorespiratory criteria. The use of neurorespiratory criteria in the law is well supported in the literature for physiologic and social reasons.
Neurorespiratory Criteria Have Worldwide Support
The decision to declare DNC arose in the context of a critical care setting, where some ventilator-dependent patients were discovered to be comatose, unable to initiate breathing, and lacking reflexes that mediate pupillary reaction to bright light, spontaneous eye-tracking of objects when the head is abruptly turned, and cough or gag responses.
27 According to the report of the 1981 President’s Commission1, which articulated justifications for the UDDA, neurologic criteria for death, like circulatory criteria, provide sufficient evidence for the patient’s death and should be used if there is reason to believe circulatory functioning does not reliably indicate the presence of life.
Many of the President’s Commission’s arguments in Defining Death1 are consistent with the neurorespiratory criterion. The phrase “whole-brain” was never meant to imply that every neuron had to fail; rather, it was meant to contrast with the so-called “higher brain” formulation, which holds that permanent loss of consciousness alone is sufficient to determine death. “What is missing in the dead,” the drafters argued, “is a collection of characteristics that all contribute to an organism’s responsiveness to its internal and external environment.” 1(p36) In their explanation of the language of “all functions of the entire brain, including the brainstem,” the relevant “cluster of attributes” becomes clearer:
This may seem redundant, but it should make clear the intent to exclude any patient who has only lost “higher” brain functions or, conversely, who maintains those functions but has only suffered a direct injury to the brain stem that interferes with the body’s vegetative functions. (original emphasis, p75)
Thus, if one is conscious or breathes spontaneously, one is not dead. While not explicitly stated, the implication is that if the cause of brain injury is known and confounding factors such as hypothermia or drug intoxication are ruled out, then permanent loss of consciousness and drive to breathe clinically indicate permanent loss of the relevant “cluster of attributes” required for an organism to live. 1(p36)
In the United Kingdom, the Academy of Royal Medical Colleges’ A Code of Practice for the Diagnosis and Confirmation of Death clearly affirms these characteristics.
28: “death has occurred when the brain-stem has been damaged in such a way and to such a degree that its integrative functions (which include neural control of cardiac and pulmonary function and consciousness) are irreversibly destroyed.”
28(p13) In terms of the definition of death, the Academy of Royal Medical Colleges states:
Death entails the irreversible loss of those essential characteristics required for the existence of a living human being; thus, death should be defined as the irreversible loss of consciousness combined with the irreversible loss of the ability to breathe.
The link between the destruction of the brainstem’s “integrative functions” and the irreversible loss of consciousness and the drive to breathe is unmistakable. Supporters of the brainstem formulation of DNC in the United Kingdom have maintained for decades that neurorespiratory criteria are philosophically and culturally accepted, not only because they are critical for continued life, but also because they represent the departure of the “conscious soul” and the “breath of life” at the neurophysiologic level. 29,30
Another landmark document that supports neurorespiratory criteria is the 2008 white paper Controversies in the Determination of Death by the President’s Council on Bioethics.
31 After reviewing the criticisms of the 1981 President’s Commission report, the President’s Council (“Position Two”) agreed that DNC should be accepted as a method of determining the loss of the organism’s capacity to perform its “vital work.” The loss of the organism’s capacity to engage in need-driven interaction with its environment, sensing what it needs (oxygen) and acting to meet those needs (striving to take in air), according to the authors, is what marks the end of the organism. 32 This vital activity was explicitly operationalized in terms of neurorespiratory criteria: “If there are no signs of consciousness and spontaneous breathing is absent, and the best clinical judgment is that these neurophysiologic facts cannot be reversed, Position Two would lead us to the conclusion that a once-living patient has now died” (emphasis original). 32(p64) Position Two, like the UK model, adds, “From a philosophical-biological standpoint, it becomes clear that a human being with a destroyed brainstem has lost the functional capacities that define organismic life.” 32(p66) Although the authors did not advocate changing the law to a “brainstem-only” formulation, they did strongly advocate using neurorespiratory criteria to determine “total brain failure” (or DNC). 33(p12)
Two other representative professional societies provide additional support for neurorespiratory criteria. In its 2006 report on the neurologic determination of death34, the Canadian Medical Association recommends that the “concept and definition of neurologic death” be defined as “the irreversible loss of consciousness combined with the irreversible loss of all brain stem functions [named elsewhere in the document], including the capacity to breathe.” 34(p3) According to the World Health Organization’s 2012 statement on death criteria, “death occurs when there is permanent loss of capacity for consciousness and loss of all brainstem functions.” 35(p31) Although the ability to breathe is not explicitly mentioned, its loss is implied because they acknowledge that “respiratory arrest” is “secondary to brainstem function loss.” 35(p13)
The World Brain Death Project (2020), an international consensus statement endorsed by 5 world federations and numerous medical societies, is the most recent highly influential publication to acknowledge neurorespiratory criteria. The members proposed that “the complete and permanent loss of brain function as defined by an unresponsive coma with loss of capacity for consciousness, brainstem reflexes, and the ability to breathe independently” be defined as “the complete and permanent loss of brain function as defined by an unresponsive coma with loss of capacity for consciousness, brainstem reflexes, and the ability to breathe independently.” 26(p1081)
The President’s Commission, the Royal Medical Colleges, the President’s Council, the Canadian Medical Association, the World Health Organization, and the World Brain Death Project all emphasized the importance of brainstem functioning for consciousness and spontaneous breathing. The overlap of functions attributable to the brainstem nuclei—emotion, wakefulness and sleep, basic attention, and consciousness itself—is critical for a living organism’s homeostatic balance. 36 The upper pons and midbrain are the primary nuclei involved in modulating cortical activation, but lower brainstem structures have also been implicated. A thorough examination of the functions of all clinically accessible brainstem nuclei raises the likelihood that consciousness and spontaneous breathing have been permanently lost.